Build a High-Performance All-Solid-State Lithium Battery through Introducing Competitive Coordination Induction Effect in Polymer-Based Electrolyte.

Polymer-inorganic composite electrolytes (PICE) have attracted tremendous attention in all-solid-state lithium batteries (ASSLBs) due to facile processability. However, the poor Li+ conductivity at room temperature (RT) and interfacial instability severely hamper the practical application. Herein, we propose a concept of competitive coordination induction effects (CCIE) and reveal the essential correlation between the local coordination structure and the interfacial chemistry in PEO-based PICE. CCIE introduction greatly enhances the ionic conductivity and electrochemical performances of ASSLBs at 30 °C. Owing to the competitive coordination (Cs+…TFSI-…Li+, Cs+…C-O-C…Li+ and 2,4,6-TFA…Li…TFSI-) from the competitive cation (Cs+ from CsPF6) and molecule (2,4,6-TFA: 2,4,6-trifluoroaniline), a multimodal weak coordination environment of Li+ is constructed enabling a high efficient Li+ migration at 30 °C (Li+ conductivity: 6.25×10-4 S cm-1; tLi +=0.61). Since Cs+ tends to be enriched at the interface, TFSI- and PF6 - in situ form LiF-Li3N-Li2O-Li2S enriched solid electrolyte interface with electrostatic shielding effects. The assembled ASSLBs without adding interfacial wetting agent exhibit outstanding rate capability (LiFePO4: 147.44 mAh g-1@1 C and 107.41mAhg-1@2 C) and cycling stability at 30 °C (LiFePO4:94.65 %@200cycles@0.5 C; LiNi0.5Co0.2Mn0.3O2: 94.31 %@200 cycles@0.3 C). This work proposes a concept of CCIE and reveals its mechanism in designing PICE with high ionic conductivity as well as high interfacial compatibility at near RT for high-performance ASSLBs.

Achieving the High Capacity and High Stability of Li-Rich Oxide Cathode in Garnet-Based Solid-State Battery.

Solid-state batteries (SSBs) based on Li-rich Mn-based oxide (LRMO) cathodes attract much attention because of their high energy density as well as high safety. But their development was seriously hindered by the interfacial instability and inferior electrochemical performance. Herein, we design a three-dimensional foam-structured GaN-Li composite anode and successfully construct a high-performance SSB based on Co-free Li1.2 Ni0.2 Mn0.6 O2 cathode and Li6.5 La3 Zr1.5 Ta0.5 O12 (LLZTO) solid electrolyte. The interfacial resistance is considerably reduced to only 1.53â€…Ω cm2 and the assembled Li symmetric cell is stably cycled more than 10,000 h at 0.1-0.2 mA cm-2 . The full battery shows a high initial capacity of 245 mAh g-1 at 0.1 C and does not show any capacity degradation after 200 cycles at 0.2 C (≈100 %). The voltage decay is well suppressed and it is significantly decreased from 2.96 mV/cycle to only 0.66 mV/cycle. The SSB also shows a very high rate capability (≈170 mAh g-1 at 1 C) comparable to a liquid electrolyte-based battery. Moreover, the oxygen anion redox (OAR) reversibility of LRMO in SSB is much higher than that in liquid electrolyte-based cells. This study offers a distinct strategy for constructing high-performance LRMO-based SSBs and sheds light on the development and application of high-energy density SSBs.

Highly efficient photodegradation of magnetic GO-Fe3O4@SiO2@CdS for phenanthrene and pyrene: Mechanism insight and application assessment.

A novel magnetic core-shell Fe3O4@SiO2@CdS embedded graphene oxide (GO) composite was prepared for the visible-light-driven photodegradation of high ring number polycyclic aromatic hydrocarbons (PAHs). The potential application of GO-Fe3O4@SiO2@CdS was evaluated through the photodegradation of phenanthrene and pyrene in deionized water, tap water, and lake water, respectively. It was found that GO-Fe3O4@SiO2@CdS could remove 86.4 % of phenanthrene and 93.4 % of pyrene, suggesting its potential for the degradation of high-ring number PAHs. The density functional theory (DFT) calculations demonstrate that pyrene has more active sites attacked by free radicals. The photoelectrochemical measurement and quenching experiments indicate that GO can transfer photoelectrons efficiently, resulting in the crucial radicals (O2-, OH and 1O2). More importantly, the photocatalytic activity kept almost constant during five cycles, confirming the significant anti-photocorrosion of GO-Fe3O4@SiO2@CdS. This work provides some new insights into the removal of PAHs with high-ring numbers in the natural water environment.

Facile one-step preparation of Co and Ce doped TiO2 in visible light PMS activation for PAHs degradation.

In this work, Co and Ce doped TiO2 (CoCeTi) with low content of Co and Ce was successfully prepared by a facile one-step sol-gel solvothermal process for activating Peroxymonosulfate (PMS) to degrade Polycyclic aromatic hydrocarbons (PAHs). The phenanthrene degradation rate was 98.2% effectively in 15 min by CoCeTi (50.0 mg/L) activation PMS (0.50 mmol/L) under visible light. SO4•-, O2•-, h+ and 1O2 were verified as the dominant reactive species for PAHs degradation. The collective effect of CoCeTi, PMS and visible light irradiation has been discussed. The possible phenanthrene degradation pathway was proposed through intermediates analysis. CoCeTi composed of Co3O4, CeO2 and TiO2 was confirmed. Outstandingly, CoCeTi/PMS/visible light system has very low cobalt (0.036 mg/L) and cerium (0.27 mg/L) leaching. Due to CoCeTi having good activated PMS properties and other excellent characteristics, it has potential application for PAHs or other organic pollutants degradation.

High-Performance Ag-Modified Bi0.5Sb1.5Te3 Films for the Flexible Thermoelectric Generator.

Bi-Sb-Te-based semiconductors possess the best room-temperature thermoelectric performance, but are restricted for application in the wearable field because of their inherent brittleness, rigidity, and nonscalable manufacturing techniques. Therefore, how to obtain thermoelectric materials with excellent thermoelectric properties and flexibility through the batch production process is a serious challenge. Here, we report the fabrication of flexible p-type thermoelectric Ag-modified Bi0.5Sb1.5Te3 films on flexible substrates using a facile approach. Their optimized power factors are ∼12.4 and ∼14.0 µW cm-1 K-2 at 300 and 420 K, respectively. These high-power factors mainly originate from the optimized carrier transport of the composite system, through which a high level of electrical conductivity is achieved, whereas a remarkably improved Seebeck coefficient is simultaneously obtained. Bending tests demonstrate the excellent flexibility and mechanical durability of the composite films, and their power factors decrease by only about 10% after bending for 650 cycles with a bending radius of 5 mm. A flexible thermoelectric module is designed and constructed using the optimized composite films and displays a power density of ∼1.4 mW cm-2 at a relatively small ΔT of 60 K. This work demonstrates the potential of inorganic thermoelectric materials to be made on flexible/wearable substrates for energy harvesting and management devices.